Historic Earthquakes: Tectonic Summary

2003 February 24 02:03:41 UTC

This earthquake occurred near the boundary between the Tarim Basin and the Tian Shan mountain range in the north-west Tarim Basin. In a broad sense, earthquakes in this region result from stresses induced by the collision of the Indian and Eurasian continental plates, even though the boundary between these plates lies about 1000 km to the south.

The Indian Plate continuously moves northward at a rate of 4.5 cm per year relative to the Eurasian Plate generating massive mountain ranges including the Himalaya and causing the uplift of the Tibetan Plateau. These stresses are transmitted to the north, through the rigid and undeforming Tarim Basin, where they generate the Tian Shan mountains and numerous earthquakes like this recent event. Several nearby mapped faults have orientations similar to the thrust fault that the earthquake occurred on, although seismologists have not yet associated the quake with a specific fault.

The region surrounding this earthquake has produced several deadly earthquakes in the past decade. The most destructive include a magnitude 6.3 event on March 19, 1996, a magnitude 5.9 on January 21, and a magnitude 6.2 on April 11, 1997. Each quake killed between 10 and 24 people, and destroyed thousands of buildings. The most recent significant earthquake occurred on August 27, 1998 killing 2 and destroying 3,600 homes.